Shahr bin Haushab reported:
I asked Umm Salamah (May Allah be pleased with her), "O Mother of the Believers! Which supplication did the Messenger of Allah (ﷺ) make frequently when he was in your house?" She said: "He (ﷺ) supplicated frequently: 'Ya muqallibal-qulubi, thabbit qalbi 'ala dinika (O Controller of the hearts make my heart steadfast in Your religion)."[At- Tirmidhi].
App reference: Book 17, Hadith 25
Arabic/English book reference: Book 17, Hadith 1489